var hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase        */
//var b64pad = ""; /* base-64 pad character. "=" for strict RFC compliance   */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */
function hex_md5(s) {
  return rstr2hex(rstr_md5(str2rstr_utf8(s)));
}
// function b64_md5(s) {
//   return rstr2b64(rstr_md5(str2rstr_utf8(s)));
// }
// function any_md5(s, e) {
//   return rstr2any(rstr_md5(str2rstr_utf8(s)), e);
// }
// function hex_hmac_md5(k, d) {
//   return rstr2hex(rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d)));
// }
// function b64_hmac_md5(k, d) {
//   return rstr2b64(rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d)));
// }
// function any_hmac_md5(k, d, e) {
//   return rstr2any(rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d)), e);
// }

/*
 * Perform a simple self-test to see if the VM is working
 */
// function md5_vm_test() {
//   return hex_md5("abc").toLowerCase() == "900150983cd24fb0d6963f7d28e17f72";
// }

/*
 * Calculate the MD5 of a raw string
 */
function rstr_md5(s) {
  return binl2rstr(binl_md5(rstr2binl(s), s.length * 8));
}

/*
 * Calculate the HMAC-MD5, of a key and some data (raw strings)
 */
// function rstr_hmac_md5(key, data) {
//   var bkey = rstr2binl(key);
//   if (bkey.length > 16) bkey = binl_md5(bkey, key.length * 8);

//   var ipad = Array(16),
//     opad = Array(16);
//   for (var i = 0; i < 16; i++) {
//     ipad[i] = bkey[i] ^ 0x36363636;
//     opad[i] = bkey[i] ^ 0x5c5c5c5c;
//   }

//   var hash = binl_md5(ipad.concat(rstr2binl(data)), 512 + data.length * 8);
//   return binl2rstr(binl_md5(opad.concat(hash), 512 + 128));
// }

/*
 * Convert a raw string to a hex string
 */
function rstr2hex(input) {
  try {
    hexcase;
  } catch (e) {
    hexcase = 0;
  }
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var output = "";
  var x;
  for (var i = 0; i < input.length; i++) {
    x = input.charCodeAt(i);
    output += hex_tab.charAt((x >>> 4) & 0x0f) + hex_tab.charAt(x & 0x0f);
  }
  return output;
}

/*
 * Convert a raw string to a base-64 string
 */
// function rstr2b64(input) {
//   try {
//     b64pad;
//   } catch (e) {
//     b64pad = "";
//   }
//   var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
//   var output = "";
//   var len = input.length;
//   for (var i = 0; i < len; i += 3) {
//     var triplet =
//       (input.charCodeAt(i) << 16) |
//       (i + 1 < len ? input.charCodeAt(i + 1) << 8 : 0) |
//       (i + 2 < len ? input.charCodeAt(i + 2) : 0);
//     for (var j = 0; j < 4; j++) {
//       if (i * 8 + j * 6 > input.length * 8) output += b64pad;
//       else output += tab.charAt((triplet >>> (6 * (3 - j))) & 0x3f);
//     }
//   }
//   return output;
// }

/*
 * Convert a raw string to an arbitrary string encoding
 */
// function rstr2any(input, encoding) {
//   var divisor = encoding.length;
//   var i, j, q, x, quotient;

//   /* Convert to an array of 16-bit big-endian values, forming the dividend */
//   var dividend = Array(Math.ceil(input.length / 2));
//   for (i = 0; i < dividend.length; i++) {
//     dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
//   }

//   /*
//    * Repeatedly perform a long division. The binary array forms the dividend,
//    * the length of the encoding is the divisor. Once computed, the quotient
//    * forms the dividend for the next step. All remainders are stored for later
//    * use.
//    */
//   var full_length = Math.ceil(
//     (input.length * 8) / (Math.log(encoding.length) / Math.log(2))
//   );
//   var remainders = Array(full_length);
//   for (j = 0; j < full_length; j++) {
//     quotient = Array();
//     x = 0;
//     for (i = 0; i < dividend.length; i++) {
//       x = (x << 16) + dividend[i];
//       q = Math.floor(x / divisor);
//       x -= q * divisor;
//       if (quotient.length > 0 || q > 0) quotient[quotient.length] = q;
//     }
//     remainders[j] = x;
//     dividend = quotient;
//   }

//   /* Convert the remainders to the output string */
//   var output = "";
//   for (i = remainders.length - 1; i >= 0; i--)
//     output += encoding.charAt(remainders[i]);

//   return output;
// }

/*
 * Encode a string as utf-8.
 * For efficiency, this assumes the input is valid utf-16.
 */
function str2rstr_utf8(input) {
  var output = "";
  var i = -1;
  var x, y;

  while (++i < input.length) {
    /* Decode utf-16 surrogate pairs */
    x = input.charCodeAt(i);
    y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
    if (0xd800 <= x && x <= 0xdbff && 0xdc00 <= y && y <= 0xdfff) {
      x = 0x10000 + ((x & 0x03ff) << 10) + (y & 0x03ff);
      i++;
    }

    /* Encode output as utf-8 */
    if (x <= 0x7f) output += String.fromCharCode(x);
    else if (x <= 0x7ff)
      output += String.fromCharCode(
        0xc0 | ((x >>> 6) & 0x1f),
        0x80 | (x & 0x3f)
      );
    else if (x <= 0xffff)
      output += String.fromCharCode(
        0xe0 | ((x >>> 12) & 0x0f),
        0x80 | ((x >>> 6) & 0x3f),
        0x80 | (x & 0x3f)
      );
    else if (x <= 0x1fffff)
      output += String.fromCharCode(
        0xf0 | ((x >>> 18) & 0x07),
        0x80 | ((x >>> 12) & 0x3f),
        0x80 | ((x >>> 6) & 0x3f),
        0x80 | (x & 0x3f)
      );
  }
  return output;
}

/*
 * Encode a string as utf-16
 */
// function str2rstr_utf16le(input) {
//   var output = "";
//   for (var i = 0; i < input.length; i++)
//     output += String.fromCharCode(
//       input.charCodeAt(i) & 0xff,
//       (input.charCodeAt(i) >>> 8) & 0xff
//     );
//   return output;
// }

// function str2rstr_utf16be(input) {
//   var output = "";
//   for (var i = 0; i < input.length; i++)
//     output += String.fromCharCode(
//       (input.charCodeAt(i) >>> 8) & 0xff,
//       input.charCodeAt(i) & 0xff
//     );
//   return output;
// }

/*
 * Convert a raw string to an array of little-endian words
 * Characters >255 have their high-byte silently ignored.
 */
function rstr2binl(input) {
  var output = Array(input.length >> 2);
  for (var i = 0; i < output.length; i++) output[i] = 0;
  // eslint-disable-next-line no-redeclare
  for (var i = 0; i < input.length * 8; i += 8)
    output[i >> 5] |= (input.charCodeAt(i / 8) & 0xff) << i % 32;
  return output;
}

/*
 * Convert an array of little-endian words to a string
 */
function binl2rstr(input) {
  var output = "";
  for (var i = 0; i < input.length * 32; i += 8)
    output += String.fromCharCode((input[i >> 5] >>> i % 32) & 0xff);
  return output;
}

/*
 * Calculate the MD5 of an array of little-endian words, and a bit length.
 */
function binl_md5(x, len) {
  /* append padding */
  x[len >> 5] |= 0x80 << len % 32;
  x[(((len + 64) >>> 9) << 4) + 14] = len;

  var a = 1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d = 271733878;

  for (var i = 0; i < x.length; i += 16) {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;

    a = md5_ff(a, b, c, d, x[i + 0], 7, -680876936);
    d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586);
    c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819);
    b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330);
    a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897);
    d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426);
    c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341);
    b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983);
    a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416);
    d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417);
    c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
    b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
    a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682);
    d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
    c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
    b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329);

    a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510);
    d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632);
    c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713);
    b = md5_gg(b, c, d, a, x[i + 0], 20, -373897302);
    a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691);
    d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083);
    c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
    b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848);
    a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438);
    d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690);
    c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961);
    b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501);
    a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467);
    d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784);
    c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473);
    b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);

    a = md5_hh(a, b, c, d, x[i + 5], 4, -378558);
    d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463);
    c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562);
    b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
    a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060);
    d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353);
    c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632);
    b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
    a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174);
    d = md5_hh(d, a, b, c, x[i + 0], 11, -358537222);
    c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979);
    b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189);
    a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487);
    d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
    c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520);
    b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651);

    a = md5_ii(a, b, c, d, x[i + 0], 6, -198630844);
    d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415);
    c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
    b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055);
    a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571);
    d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606);
    c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
    b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799);
    a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359);
    d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
    c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380);
    b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649);
    a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070);
    d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
    c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259);
    b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551);

    a = safe_add(a, olda);
    b = safe_add(b, oldb);
    c = safe_add(c, oldc);
    d = safe_add(d, oldd);
  }
  return Array(a, b, c, d);
}

/*
 * These functions implement the four basic operations the algorithm uses.
 */
function md5_cmn(q, a, b, x, s, t) {
  return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}
function md5_ff(a, b, c, d, x, s, t) {
  return md5_cmn((b & c) | (~b & d), a, b, x, s, t);
}
function md5_gg(a, b, c, d, x, s, t) {
  return md5_cmn((b & d) | (c & ~d), a, b, x, s, t);
}
function md5_hh(a, b, c, d, x, s, t) {
  return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a, b, c, d, x, s, t) {
  return md5_cmn(c ^ (b | ~d), a, b, x, s, t);
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safe_add(x, y) {
  var lsw = (x & 0xffff) + (y & 0xffff);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xffff);
}

/*
 * Bitwise rotate a 32-bit number to the left.
 */
function bit_rol(num, cnt) {
  return (num << cnt) | (num >>> (32 - cnt));
}

module.exports = {
  b64Md5: hex_md5
};